$prepared_args = array(
  'number'  => $request['per_page'],
  'post_id' => $request['post'] ? $request['post'] : '', // <--- Not authenticated
  'parent'  => isset( $request['parent'] ) ? $request['parent'] : '',
  'search'  => $request['search'],
  'orderby' => $this->normalize_query_param( $order_by ),
  'order'   => $request['order'],
  'status'  => 'approve',
  'type'    => 'comment',
);

$prepared_args['offset'] = $prepared_args['number'] * ( absint( $request['page'] ) - 1 );

if ( current_user_can( 'edit_posts' ) ) {
  $protected_args = array(
    'user'         => $request['user'] ? $request['user'] : '',
    'status'       => $request['status'],
    'type'         => isset( $request['type'] ) ? $request['type'] : '',
    'author_email' => isset( $request['author_email'] ) ? $request['author_email'] : '',
    'karma'        => isset( $request['karma'] ) ? $request['karma'] : '',
    'post_author'  => isset( $request['post_author'] ) ? $request['post_author'] : '',
    'post_name'    => isset( $request['post_slug'] ) ? $request['post_slug'] : '', // <--- Authenticated :(
    'post_parent'  => isset( $request['post_parent'] ) ? $request['post_parent'] : '',
    'post_status'  => isset( $request['post_status'] ) ? $request['post_status'] : '',
    'post_type'    => isset( $request['post_type'] ) ? $request['post_type'] : '',
  );

  $prepared_args = array_merge( $prepared_args, $protected_args );
}